FIG. 1 shows diagrams of assistance in explaining a laminate to which the present invention is applied; (A) being a front view and (B) a plan view. FIG. 2 shows cross-sectional diagrams taken on lines in FIG. 1(A); FIGS. 2(A) through (E) showing cross-sectional views taken on lines A—A, B—B, C—C, D—D and E—E, respectively.
When manufacturing a laminate 100 as shown in FIG. 1 with a steel material, for example, parts having a circular cross section as shown in FIGS. 2(B) and (D) can be turned with a lathe, but the manufacture of parts having regular tetragonal, orthohexagonal and quasi cruciform cross sections as shown in FIGS. 2(A), (C) and (E) involves extremely complicated machining operations requiring great man-hours and time.
It is cumbersome and complicated, or sometimes even totally impossible, to machine a laminate 100 having the aforementioned construction from a sold round bar or a block piece. For this reason, there can be a method of dividing the laminate 100 into a plurality of component members, machining these members, and assembling the machined members into one piece. If the laminate 100 is of a small size, however, assembling such machined members might be impossible.
Casting, for example, is sometimes employed to manufacture the aforementioned laminate 100 having a complex shape. The manufacture of the laminate 100 by casting involves multiple processes, such as preparing a model, forming a casting mold based on the model, and pouring molten metal into the mold, requiring a lot of man-hours and time.
Even when a precision casting method, including lost-wax process, is employed, it is difficult to maintain high precision and produce a highly smooth casting surface. This necessitates finishing the cast surface, leading to increased cost to manufacture the laminate 100.
To solve the abovementioned problem, the present Applicant had already filed a patent application in Japan for an invention of manufacturing laminates having multiple cross-sectional shapes by progressively transferring (indexing) a hoop-shaped long-sized workpiece in the longitudinal direction, punching a plurality of component members having the contours corresponding to the cross-sectional shapes of the laminate, temporarily holding the punched component members on the punched holes of the workpiece by pushback, sequentially stamping out the component members in the final stage of the indexing of the workpiece, and assembling the component members into one piece (Japanese Unexamined Published Patent Application No. Hie-10(1998)-235598).
However, it was found that there still remain some problems in the improvement patent. That is, since the punched component members are temporarily held on the punched hole only by frictional force between the member and the hole, the punched component members may sometimes come off from the punched holes due to vibrations during indexing or some other reasons, interrupting the indexing operation.
Furthermore, the punched component members may be slightly deformed or subjected to dimensional changes when pushed back to replace to the punched holes.
The present invention is intended to overcome the aforementioned problems, and it is an object of the present invention to provide a method for relatively easily manufacturing laminates by continuously forming a plurality of component members having different cross-sectional shapes.
It is another object of the present invention to provide a method for manufacturing laminates in which the bonding strength of a laminate made by continuously forming and laminating a plurality of component members having different cross-sectional shapes can be easily increased.
It is still another object of the present invention to provide an apparatus for relatively easily manufacturing laminates by continuously forming a plurality of component members having different cross-sectional shapes.
It is a further object of the present invention to provide an apparatus for manufacturing laminates in which the bonding strength of the laminate made by continuously forming and laminating a plurality of component members having different cross-sectional shapes can be easily increased.